This is a blend file which contains blender pose libraries for the Second Life avatar. These libraries can be used to create animations for your own projects, or used to check weights when rigging clothing, or whatever else you might need them for. Most are poses, but there are some popular animations that might be useful.

To install them into your own blend file, just choose Append instead of Import, and then find this blend file on your computer. Click on it and it should show you the files inside, choose Action, then choose 1 of the files there, like Medhue Poses. These poses only work on the Second Life avatar. « Less